I just paid for it today. The primary reason being that, for $3 I couldn't justify not supporting the author of such an important and useful app in my daily Android experience. The more money he makes from this project, the more he'll be encouraged to improve it which helps me. For the cost of a single soda/juice/coffee, it'd be ridiculously selfish and cheap of me not to toss a few coins his way.
Some people are way too stuck on the whole "all software should be free" mindset. It's selfish and rude, and hurts that person and everyone else. Hypocritical too, given what the same person will blow $5-$10 on without thinking twice.
I'm going to check out the perks I get now for features, but even if I don't use any that's fine by me.